Intake fittings for the fuel tanks of motor vehicles are, as a rule, closed with a tank cap. To fill the tank with fuel, the tank cap must be opened. When this is done, the soiling of the hands, especially with diesel fuel, is not always to be avoided. In order to prevent such soiling and generally to increase tank friendliness, intake fittings have been proposed which possess no screw-on or clip-on tank caps but exhibit a locking cap, which, when impelled by a penetrating fuel hose nozzle, swings inward against the action of a spring. In its closed position, the closure flap lies on a sealed seat.
In order to prevent an unwarranted opening of the closure flap, DE 198 02 592 disclosed an intake fitting provided with a locking arrangement of the closure flap. In this arrangement, the closure flap is provided on its inner side with a catch having a reach-through opening. By means of a radial boring in the intake fitting, a locking pin passes through to the inside, there engaging in a recess of the catch. Thus, the closure cap is locked in its closed position. The disadvantage of this is that additional sealing means are necessary.
In the conventional intake fittings, the sidewall of the fitting possesses an opening from an axle boring. Between the outer wall of the intake fitting and this entry is a sealing ring to prevent the escape of fuel vapors. In the interior of the intake fitting, between the forward end of the axle, which forms the locking bolt and an inwardly extending section thereof, the installation of a sealing ring has been arranged. In spite of this complex and expensive sealing measure, an escape of fuel vapor is still not entirely prevented.
Thus, an objective of the invention is to propose an intake fitting with a closure flap with improvements to prevent the escape of fuel vapor.
The object is achieved by an intake fitting possessing the features of the invention. In accord with this, there has been provided a locking mechanism on the outer side of the closure flap which, in the closed position, stands in contact with the ambient atmosphere. Because of this construction, the locking mechanism is accessible from the outside so that a penetration through the intake fitting, as taught by DE 198 02 592 with its attendant disadvantages, especially in regard to the escape of fuel vapors, is no longer necessary. The locking mechanism, which, for example, can be installed in a conventional intake fitting, prevents an unauthorized opening without increasing the escape of fuel vapors.
In a preferred embodiment, there is at least one locking element installed on the closure flap, whereby the flap is hingedly movable between a position of full closure and a free opening. In the locked position, the concept is that an apparatus arrests the closure flap in a closed position; i.e., a co-action is in effect between a detent engaging an arresting means in the direction of the longitudinal centerline axis of a seat for a sealing element. The longitudinal centerline axis of the sealing element is, of course, also the centerline axis of the intake fitting. With this embodiment, of course, the essential elements of the closure flap locking mechanism are already in place, so that limitations of design measures in the adjacent bodywork are minimized. Essentially, a body-side initiation for the activation of the locking mechanism is provided, wherein this activation drive can be supplied by very simple measures, i.e., in the form of a Bowden cable or the like.
Advantageously, a spring element is provided, which loads the locking mechanism in essentially an axial direction when the locking mechanism is in the locked position. Accordingly, the closure flap is pressed against the seat of the sealing element and pressure increases the impermeability at that location. Tolerance variations in manufacture are compensated for by the spring. Advantageously, the rim which circumferentially surrounds the opening of the intake fitting also serves as the detent for the opening. This design is particularly advantageous in consideration of the expense of manufacture. In this way, the installation, or the molding on, of additional abutting detents can be dispensed with.
The spring element, in the case of a particularly favored embodiment, is designed as an annular spring circumferentially placed about the rim of the opening and compressible in an axial direction. An annular spring of this design permits, in a relatively simple way, its affixation on the opening rim in both radial and axial directions. Furthermore, the annular spring can be so constructed that it exercises the same spring force at each point of its circumference on a co-acting locking mechanism.
In an advantageous embodiment, on the end of the annular spring which leads its motion, an axial movable slider ring is installed. The side of this slider ring, which is remote from the spring, is spring loaded in the locking position of the locking mechanism. Advantageously, an annular spring, somewhat of the order of a circumferentially, accordion pleated, leaf spring can be employed, which would also exhibit a pre-domed section in its axial direction. By means of the slide ring, first, a circumferential distribution of the spring force is assured, and second, the uniform co-action with a locking element at a practically optional point on the circumference can be effected.
In the case of a further, preferred embodiment, two locking elements are provided, which are constructed as pivoting arm locking components. These locking elements can be pivoted within a pivot plane somewhat parallel to and at an axial distance from the extended plane of the opening rim. In a case with two annular springs, a symmetrical compression becomes possible if the pivoting arms engage the opening rim with their outer lying locking ends, that is, the slider ring, at diametrically oppositely disposed points. In doing this, it is advantageous if the inner lying ends of the pivoting arms overlap and are penetratively joined by a common axle in the center of the closure flap in such a way that they are thus coaxial with the pivoting axle, which in turn is coaxial to the center axis of the intake fitting.
In order to make the opening of the closure flap possible, it is necessary that the pivoting arms, in their released position, be so positioned on the outside of the closure flap that this flap can unobstructedly be swung inwardly into the intake fitting by the fuel hose nozzle. This advantage is achieved by the fact that the pivoting axle is movable in a continuous radial direction, symmetrical to the pivoting arms. Thus, the movement of the pivot axle is coupled with the movement of pivoting arms. If the pivoting axle starting from the locked condition moves radially outward,somewhat through a body side activation element, then at the same time the pivot arms are swung inward, they become positioned centrally on the outside of the closure flap in such a manner that their respective opening movements are not obstructed. The radial movement of the pivoting axle and the pivoting of the pivot arms are preferably realized in that the former with at least one end engages in a radially running guide groove. The latter with respectively one control pin engages into a control groove in the plane of the guide groove, which runs at an angle to the plane. These grooves are in this arrangement so positioned that they enclose between them an angle opening toward the center axis.
In an advantageous positioning of the pivoting arms, from the point of view of manufacturing technology, these arms are between two bearing plates running parallel to the pivoting plane of the arms. In the inner surfaces of the bearing plates are, respectively, one guide groove and two control grooves. During the assembly, the parts can simply be set, one into the other, wherein the pivoting axle has its ends engaged in the guide grooves and the pivoting arms have their control pins running in the control grooves.
Additional measures for affixing are necessary. The components protruding out of the bearing plates and out of the pivot arms permit, in a simple manner, a fastening on the outside of the closure flap. A further advantage is found in that the pivoting arms are protected from damage by the fuel hose nozzle by the bearing plates which were installed outside of and above said arms. An advantageous possibility of affixing the components on the closure flap can be found therein in that on the edge of the upper bearing plate, as seen in the assembled condition, an apron is formed which encompasses the pivoting arms. The free ends of the arms, in this case, are respectively fixed on the closure flap outer side.
The apron exhibits two window-like openings through which the pivoting arms in the closed position pass. The apron offers a lateral mechanical protective barrier, which diminishes the danger that in an accident the locking mechanism of the closure flap will open. The same purpose is served by the arrest device of the pivoting arms at their end positions. If, for instance, in an accident, the locking mechanism, i.e., the pivoting arms, are separated from their drive, then the arrest device prevents a situation in which the arms can, without any restrictions, immediately move into their released position. Advantageously, this arrest condition is achieved by a bar spring, which is located in an interposed space between the lower bearing plate and the closure flap outside. The bar spring with a V-shaped longitudinal section, engages itself in the movement path of the guide groove of the lower bearing plate in which the penetrating pivot axle runs.
For the activation of the pivoting arms, there are several possibilities available. It is somewhat worthy of consideration that activation elements could be placed on the free ends of the pivoting arms. In the case of a preferred embodiment, however, two opposed hooks are placed on the outer sides of the inner ends of the said pivoting arms, which overlap each other in an axial and radial direction. To effect the movement of the pivoting arms, there is provided a radially extending activation rod, which, with its own hook arrangement on the end, engages the aforesaid hooks. In order to make possible an opening of the closure flap, when the pivoting arms are in their release position, it is necessary that the activation rod be separated from the hooks. Advantageously, such a separation is attained in that the hooks possess such a length that in the release position of the pivot arms, they no longer overlap. In this situation, the free ends of the hooks are distanced, one from the other, to such an extent that they are found outside of the movement path of the end sections of the activation rod. These hooks can now be separated from the pivot arms and moved radially outward until they are in a radial position beyond the swinging zone of the closure flap. Further, the activation rods can also be moved radially to the extent that they avoid being damaged upon the insertion of the fuel hose nozzle.
As mentioned, in the case of an accident, means must be provided to prevent the release of the locking mechanism of the closure flap. By means of a tube-shaped protective sheath affixed to the intake fitting and circumferentially surrounding the locking mechanism, the inferred danger is essentially reduced, especially when the protective sheath is made of metal and is welded to a metal intake fitting.
Besides an increased crash safety feature, this construction has the additional advantage in that the permeation value can be further depressed, since metal is absolutely impermeable for fuel vapors. Still within this concept, it can be further advantageous to make the filling tube, which is affixed to the intake fitting, of metal. In the case of accident-caused deformation of the vehicle in the area of the intake fitting, consideration should be given to the fact that the activation rod can be similarly deformed so that it unlocks the closure flap. In order to prevent this, a break-away section is provided in the activation rod.
In order to ease the insertion of the fuel hose nozzle into the filling opening and to avoid damage to the sealing zone of the intake fitting by a catching of the nozzle, in the case of a preferred embodiment, an intake funnel is provided. The intake funnel, together with the intake fitting on the tank, can be closed by an existing sealing element which is on the inside of a closure flap to seal off the tank.
In order to avoid an elevated pressure within the tank that makes the opening of the closure flap difficult, or even completely prevents such opening, an apparatus co-acting directly or indirectly with the outside of the closure flap has been provided. With this apparatus the closure flap is movable in a small space between its sealing element and the seat thereof in a free interposed position. An internal tank pressure can relieve itself through this opening. Beyond this, in this interposed position of the closure flap, during the withdrawal of the fuel hose nozzle from the intake fitting, after a completed tank filling operation, drainage drippings of the fuel can flow into the tank.